/**
 * @param {number} m
 * @param {number} n
 * @return {number}
 */

var uniquePaths = function (m, n) {
    // 初始化结果数据
    let dp = new Array(m).fill(0)
    for (let i = 0; i < m; i++) {
        dp[i] = new Array(n).fill(0)
    }
    for (let i = 0; i < m; i++) {
        for (let j = 0; j < n; j++) {
            // 最上边
            if (i === 0) {
                dp[i][j] = 1
            } 
            // 最左边
            else if (j === 0) {
                dp[i][j] = 1
            } else {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1]
            }
        }
    }
    return dp[m - 1][n - 1]
};
console.log(uniquePaths(3, 7))